Does proprietary knowledge protection (PKP) spur or hinder the product-market performance of new firms? Exploiting the staggered adoptions of the inevitable disclosure doctrine by U.S. State Courts, which enhance PKP, we show that treated firms increase industry-adjusted sales growth by 2% compared to control firms. The effect is concentrated among small and young firms and increases with the scope of proprietary knowledge and rivals’ access to external finance. PKP encourages firms to develop new products and stimulates initial public offering activity. Our results suggest that PKP alleviates predation risk associated with “deep-pocket” rivals by allowing firms to maintain competitive advantages.

We document a novel strategic motive for family business groups to utilize their internal capital markets (ICMs) during financial crises. We find that crisis-period group ICM activity is targeted toward exerting product market dominance over standalone rivals. Groups make significant post-crisis gains in market share that are concentrated among affiliates (and industry segments within affiliates) operating in highly competitive product markets, where capturing such gains is difficult in normal times. These patterns are observed only in emerging markets, suggesting that ICMs enable groups to exploit crises to realize long-term competitive advantages only when rivals face chronic financing frictions.

We investigate whether international operations enhance information links between firms and foreign investors. Exploiting novel subsidiary-level data and within-location variations, we show that, after expanding into another country, a firm attracts greater investment allocation from funds from that country than from other foreign funds. This increase is economically significant, equivalent to one-fifth of the average firm weight in a country-specific portfolio. The observed effect cannot be attributed to funds’ influence, persists even when funds are already familiar with the firm, and helps them generate superior risk-adjusted returns. Our results suggest that firms’ cross-border economic activities contribute to global financial interconnectedness.

Hand hygiene is a simple, low-cost intervention that may lead to substantial population-level effects in suppressing acute respiratory infection epidemics. However, quantification of the efficacy of hand hygiene on respiratory infection in the community is lacking. We searched PubMed for randomised controlled trials on the effect of hand hygiene for reducing acute respiratory infections in the community published before 11 March 2021. We performed a meta-regression analysis using a Bayesian mixed-effects model. A total of 105 publications were identified, out of which six studies reported hand hygiene frequencies. Four studies were performed in household settings and two were in schools. The average number of handwashing events per day ranged from one to eight in the control arms, and four to 17 in the intervention arms. We estimated that a single hand hygiene event is associated with a 3% (80% credible interval (−1% to 7%)) decrease in the daily probability of an acute respiratory infection. Three of these six studies were potentially at high risk of bias because the primary outcome depended on self-reporting of upper respiratory tract symptoms. Well-designed trials with an emphasis on monitoring hand hygiene adherence are needed to confirm these findings.

Large, ‘complex’ pre-Neolithic hunter-gatherer communities thrived in southern China and northern Vietnam, contemporaneous with the expansion of farming. Research at Con Co Ngua in Vietnam suggests that such hunter-gatherer populations shared characteristics with early farming communities: high disease loads, pottery, complex mortuary practices and access to stable sources of carbohydrates and protein. The substantive difference was in the use of domesticated plants and animals—effectively representing alternative responses to optimal climatic conditions. The work here suggests that the supposed correlation between farming and a decline in health may need to be reassessed.

Strongyloidiasis is a neglected tropical disease caused by the roundworm Strongyloides stercoralis affecting 30–100 million people worldwide. Many Southeast-Asian countries report a high prevalence of S. stercoralis infection, but there are little data from Vietnam. Here, we evaluated the seroprevalence of S. stercoralis related to geography, sex and age in Vietnam through serological testing of anonymized sera. Sera (n = 1710, 1340 adults and 270 children) from an anonymized age-stratified serum bank from four regions in Vietnam between 2012 and 2013 were tested using a commercial Strongyloides ratti immunoglobulin G ELISA. Seroreactivity was found in 29·1% (390/1340) of adults and 5·5% (15/270) of children. Male adults were more frequently seroreactive than females (33·3% vs. 24·9%, P = 0·001). The rural central highlands had the highest seroprevalence (42·4% of adults). Seroreactivity in the other regions was 29·9% (Hue) and 26·0% and 18·2% in the large urban centres of Hanoi and Ho Chi Minh City, respectively. We conclude that seroprevalence of S. stercoralis was high in the Vietnamese adult population, especially in rural areas.

Let ( $\rm L$ ;C) be the (up to isomorphism unique) countable homogeneous structure carrying a binary branching C-relation. We study the reducts of ( $\rm L$ ;C), i.e., the structures with domain $\rm L$ that are first-order definable in ( $\rm L$ ;C). We show that up to existential interdefinability, there are finitely many such reducts. This implies that there are finitely many reducts up to first-order interdefinability, thus confirming a conjecture of Simon Thomas for the special case of ( $\rm L$ ;C). We also study the endomorphism monoids of such reducts and show that they fall into four categories.

Theory suggests that controlling shareholders can influence firm value through both shared benefits creation and private benefits consumption. Using negotiated control-block transfers from 31 countries, we look beyond ownership concentration and investigate how controlling shareholder heterogeneity influences the relative importance of these two effects. We document that a control transfer precipitates positive firm outcomes particularly when the vendor has maintained control over an extended period and the acquirer displays a strong incentive to engage in restructuring. In such cases, we observe a sustained positive price reaction, more focused corporate investments, lower leverage, higher operating efficiency, and superior long-term performance.

This study examines the hypothesis that the stopping rule – a traditional postnatal sex selection method where couples decide to cease childbearing once they bear a son – plays a role in high sex ratio of last births (SRLB). The study develops a theoretical framework to demonstrate the operation of the stopping rule in a context of son preference. This framework was used to demonstrate the impact of the stopping rule on the SRLB in Vietnam, using data from the Population Change Survey 2006. The SRLB of Vietnam was high at the level of 130 in the period 1970–2006, and particularly in the period 1986–1995, when sex-selective abortion was not available. Women were 21% more likely to stop childbearing after a male birth compared with a female birth. The SRLB was highest at parity 2 (138.7), particularly in rural areas (153.5), and extremely high (181.9) when the previous birth was female. Given the declining fertility, the stopping rule has a potential synergistic effect with sex-selective abortion to accentuate a trend of one-son families in the population.

This study constructs a firm-level measure of large foreign ownership (LFO) and investigates its impact on stock return volatility in 31 emerging markets. We find a negative relationship between LFO and volatility, even after controlling for potential endogeneity and the impact of major domestic shareholders. This suggests a stabilizing role of LFO in emerging markets, which is consistent with previous suggestions in the literature on the strong commitments and potential monitoring role of large foreign shareholders. Overall, our study highlights the importance of recognizing the heterogeneity among foreign investors and the benefits of large foreign shareholders to emerging stock markets.

In recent years Vietnam has experienced a high sex ratio at birth (SRB) amidst rapid socioeconomic and demographic changes. However, little is known about the differentials in SRB between maternal socioeconomic and demographic groups. The paper uses data from the annual Population Change Survey (PCS) in 2006 to examine the relationship of the sex ratio of the most recent birth with maternal socioeconomic and demographic characteristics and the number of previous female births. The SRB of Vietnam was significantly high at 111.4 (95% CI 109.7–113.1) for the period 1st April 2000 to 31st March 2006. Multivariate analysis reveals that sex of the most recent birth is strongly related with the number of previous female births. This association is consistent across different socioeconomic and demographic groups of women. Given the high SRB in Vietnam, further research into the reasons for high SRB in these groups is required, as are intervention programmes such as those raising the public awareness of its negative consequences.

For a long time pesticides attracted interest from the Vietnamese governments and farmers for their positive effects in protecting crop yield losses resulting from pests and other plant diseases. Recently, the negative effects of pesticides on human health, natural food chains and the environment are increasingly being taken into account by both state and non-state actors. Striking a balance between positive and negative effects is complicated as, most likely, pesticides will continue to maintain their vital role in an agriculture-based country such as Vietnam. However, recently a shift can be noticed in farmers' selection and application of pesticides, initiated mainly by farmers themselves and to a lesser extent also by other actors such as the government, pesticide companies and distributors. This article provides an empirical insight into this shift, based on the results from research in four provinces in the Red River Delta. Possible implications for policies toward greening pesticide handling practices in vegetable production are drawn, such as removing inexpensive pesticides (often associated with high toxicity) from the market, giving technical training on pesticide selection and use to farmers, and reconsidering the role different actors can play in future safe vegetable production programs.